This research examines the role of neurotrophin ligand-receptor systems in the adult mammalian brain after chronic exposure to ethanol and repeated episodes of withdrawal. The central hypothesis behind this research is that ethanol targets neurotrophin systems. Utilizing enzyme-linked immunosorbent assays (ELISA), Western immunoblotting, and immunohistochemistry to study protein abundance and localization, along with complementary studies using molecular methods (RT-PCR and in situ hybridization) will reveal the effects of ethanol on neurotrophin ligand and receptor expression. The experiments outlined here will provide critical information to our understanding of neurotrophin signaling in adult cortex and hippocampus under conditions of ethanol intoxication and withdrawal. Learning more about the plastic changes in the adult brain is not only relevant to understanding the pathology of withdrawal and alcohol-associated brain damage and other neurodegenerative conditions. It is also important for discerning the process of other normal functions that require synaptic remodeling such as learning and memory.